Pressure actuated switch



6 b E, m0 M 5, m n 2 m L B O I BQ!!! O ...d C M L31. MY m A B WU m l U wl 2 4 f U T 2J Y W DA. C. w1 S. Lum M a .//VJ J u. n a 6\k\k\\\\\\\\\ mm @a a@ a F m .d Q

May 22, 1951 Patented May 22, 1951 UNITED STATES; PATENT OFFICE,

PRESSURE ACTUATED SWITCH Jacob L..Pauly, Hasbrouck Heights, N. J.,assignor to Bendixl Aviation Corporation, Teterboro, N. .1., acorporation of Delaware Application December 2, 1948, Serial No. 63,060

3.Cla-ims.A (Cl. 200-83) vide: a; sensitivefpressure actuated switch.operable on pressures between. 6 inches: of' water 4pressure and 25pounds persquare inch encountered in oxygen demand. regulators.

A further object of myinventionis to pro videv a pressure actuated.switch' of Vthe. `character indicated in which: thel pressure of theluidifa'cts' against a diaphragm .and calibratedspring; and?v in whichno' back: pressure.: is built up 'by'v the movement of the diaphragm.

Another object of thisfinventionis=t01f provide' a pressurev actuatedVswitch of thecharacterz'irrdi'- cated in which the friction of movingparts is reduced to'a minimum duetto thelarge bearing surfacesprovidedtherein.

Stilllanother `obi ect oi i my inventionxis to. provide a. pressureactuated.. switchfoifthe cha-rac ter indicated in which theidiaphraginactediuponv by the fluid. pressure in turn acts upon a piston surfacehaving approximately the same area as the diaphragm to insurepositiveaction of the switch in response to duid pressures.;

Still a further object of the invention is to*v provide a pressureactuated. switch. of. the character described in whichv the response ofthe switchftooperating pressures may be varied Yet another objectief myinvention istofprovidefa pressure actuated. switch which shall. consistAof few` and simple parts; relatively inex pensive to manufacture,.automa-tic'. and positive in its operation, which shall`havefa-largevariety of application and VYyet be practical andefiicientto ahigh degree inv use.

Other objects of the invention will in` part'be obvious, and in partvhereinafter. pointed out.

The invention accordingly consists in the features of construction,combinations.. of'.`e1e' ments'andV arrangem'entof parts which Willbeexemplified in the construction hereinafter described and of which thescope of application will be indicated in the appended claims.

In the accompanying drawing forming a part of this specification inwhich one of the various illustrative embodiments of my invention isshown as a longitudinal cross-sectional View with portions shown inelevation, the numeral II] designates a pressure actuated switchenclosed in a housing II which is iixed to a mounting ange I2 as byscrews I3.

The mounting flange I2 is provided with a threadedstud: I4 and formedwith anopening or. port I5 through whiohthe'iiuid pressurexis The.housing.

introduced .into the' housing Il: II iszprovided with an integral angeIxat the base thereof, said flange being formed.. with dependentannular.` member.V I'I. the housing I I to they mountingY ilange. I2?the dependent member I'I forms. a cham'berf29fbe-- tween the ange andthehousing. A' resilient diaphragm ZI is fastened between the mount-v ingflange I2A and the dependent member 'I'I' byV the screws I3. thediaphragm.' 2l being.r thus adapted to be expanded". to thedottedflineiposi tion shown upon an increase inpressure through.

the port I5;

Fixed withinthe housing.' I I andflongitudinally disposed therein is asleeve 2E formed with.:elonr gated slots' 26; for'the; purposes;hereinafter appearing. The upper end'of thefsleevezi-25fispr vided witha threaded. portion. 2,..an; adjustment nut 219 being threaded: thereon.

Slidably received within the sleeve 2.5i is a piston 3B, the upper end'3l ofthev piston. ex-

tending slightly; above the upper end.Y of.' they sleeve 25. Fixed tothe lower end of the piston 30 assby screw 33 is arigid abutment plate35,

said-abutment `plate being within the diaphragmv chamber 20. Fixed tothe upper end 3I of the piston is an abutment pin 38. The movement ofthe piston 3] within the sleeve 251s limited by apin 40 passing throughsaid piston and registering in the slots 25 of the sleeve. Two

spring retainers il and 42 are provided` aboutv the sleeve 25, the oneabutting the nut 29', thel other abutting the pin 4G. A. coilcompression spring 43 woundv about the sleeve 25 and interposed betweenthe two retainers 4| and 42 tends to urge the piston 30 and its abutmentplate' 35 in a downward direction against the diaphragm 2i.

The increasing pressure acting upon the dia*- phragm 2l through theportiI5l will tend toraise the diaphragm 2l. rThe diaphragm will pressagainst the abutment plate 35 to move the piston 3| against the actionof the spring 43. It will be appreciated that the area of the abutmentplate 35 is approximately that of the diaphragm 2| so that any pressureof the fluid acting upon the diaphragm is transmitted directly to thepiston 30.

The movement of the abutment plate 35 within the chamber 20 willcompress any air entrapped above the abutment plate 35. The compressionof this entrapped air would tend to oiTer a greater resistance to themovement of the piston In fastening` 30. To offset the cushioning effectof the entrapped, air ports 45 are provided in the bottom wall of thehousing l l interconnecting the chamber with the interior of thehousing. Any air now that is behind the abutment plate will be forcedthrough the ports into the interior of the casing Il, the larger volumeof the casing l preventing any cushioning effect as previouslydescribed.

Fixed across the top of the housing Il as by screws 48 is a mountingplate 49. Fixed to the underside of the plate 49 is a contact assembly50 comprising an insulating plate 5l, a stationary contact 52 and aU-shaped leaf spring 53 carrying at its free end a contact 54. Anelectrical coupling 56 is mounted to the top of plate 49 for connectingthe contacts 52 and 54 to an external electrical circuit (not shown)whereby a signal or alarm may be given upon engagement of the twocontacts.

The upward movement of the piston 36 due to the expansion of thediaphragm 2l will carry the abutment pin 38 upwardly to engage the outerend of the leaf spring 53. The leaf spring will be compressed so thatthe moveable contact 54 will be brought into engagement with the xedcontact 52. A fall in pressure within the chamber 2l) will permit thespring 43 to return the piston 30 to its neutral or normal positionpermitting the contacts 52 and 54 to disengage thereby breaking theelectrical circuit.

It will be apparent that the position of the nut 29 on the sleeve 25will determine the bias of the spring 42. Thus the pressure at which thecontacts 52 and 54 will engage can be regulated by screwing the nut 29into various positions along the sleeve.

It will thus be seen that there is provided a pressure actuated switchin which the several objects of this invention are achieved and which iswell adapted to meet the conditions of practical use.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

l. A pressure actuated switch comprising a housing, a mounting for saidhousing, said housing and said mounting forming a chamber therebetween,a diaphragm within said chamber, a port in said mounting adapted to beconnected to a fluid pressure source and registering with said chamber,a sleeve longitudinally disposed in said housing and provided withelongated slots therein, a piston within said sleeve, abutment means xedto said piston and protruding through said slots, means adjustably iixedexternally to said sleeve in spaced relation to said slots, a platedisposed in said chamber adjacent said diaphragm and aixed to one end ofsaid piston, biasing means interposed between said abutment means andsaid adjustable means and disposed externally of said sleeve for biasingsaid plate into engagement with said diaphragm, and a switch adapted tobe actuated by the other end of said piston upon movement thereof bysaid diaphragm.

2. A pressure actuated switch comprising a housing, a mounting for saidhousing, said housing and said mounting forming a chamber therebetween,a diaphragm within said chamber, a port in said mounting adapted to beconnected to a fluid pressure source and registering with said chamber,a sleeve longitudinally disposed in said housing and provided withelongated slots therein, means adjustably xed externally to said sleeveadjacent one end thereof, a piston within said sleeve, a pin aixed tosaid piston and protruding through said slots, a plate disposed in saidchamber adjacent said diaphragm and afxed to the one end of said pistonremote from said one end of said sleeve, means externally of said sleeveinterposed between said pin and said adjustable means for biasing saidplate into engagement with said diaphragm, and a switch adapted to beactuated by the other end of said piston upon movement thereof by saiddiaphragm.

3. A pressure actuated switch comprising a housing having a chamberformed therein, a mounting secured to said housing so as to form asecond chamber therebetween, a diaphragm secured between said housingand said mounting within said second chamber, a port in said mountingadapted to be connected to a iiuid pressure source and registering withsaid second chamber, a sleeve longitudinally disposed in said housing, apiston within said sleeve, a plate secured to said piston movabletherewith within said second chamber and adapted to be engaged by saiddiaphragm, a plurality of cushioning eliminating ports interconnectingthe two mentioned chambers so that actuation of said plate by saiddiaphragm provides negligible resistance to the displacement of saidplate, and a switch adapted to be actuated by the other end of saidpiston upon movement thereof by said diaphragm.

JACOB L. PAULY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 956,679 Champ et al May 3, 19101,033,900 Janette July 30, 1912 1,340,646 Anderson May 18, 19201,710,859 Burks Apr. 30, 1929 2,136,504 Hilbert et al Nov. 15, 193182,343,245 Satterlee Mar. 7, 1944 2,393,455 Beeman Jan. 22, 19462,422,342 Dillman June 17, 1947 FOREIGN PATENTS Number Country Date656,557 France May 27, 1930

